In a conventional electrophotographic image forming apparatus such as an electrophotographic copying machine or a printer, fine particles of toner are used as a developer. When the toner in a main assembly of the electrophotographic image forming apparatus is used up, the toner is supplied into the main assembly of the image forming apparatus using a toner accommodating container (toner supply container).
Because the toner is in the form of very fine powder, it is known to place, upon a toner supplying operation, a toner supply container inside the main assembly of the image forming apparatus and to gradually supply the toner through a small opening to avoid scattering of the toner.
Any one of the above-described toner supply containers receives a driving force from the main assembly of the image forming apparatus to drive a feeding member in the toner supply container or a main body itself to discharge the toner.
As for such a drive transmitting means, there are many existing conventional mechanisms. For example, such a conventional mechanism is disclosed in U.S. Pat. No. 7,647,012 and shown in FIGS. 1-2. It is understood that a toner bottle 1 is generally cylindrical, and one end thereof is provided at a center with an opening 1a by a projected portion. The diameter of the opening 1a is smaller than the diameter of a cylindrical portion 1A, which is a main body of the bottle. The opening 1a is plugged with a sealing member 2 for sealing the opening 1a, which is configured such that the opening 1a is unsealed and resealed automatically by the sliding motion of the sealing member 2 relative to the toner bottle 1 in the longitudinal directions (arrows a and b) of the toner bottle 1.
At the free end portion of the sealing member 2, there is formed a cylindrical portion having an engaging projection 3 and a releasing force receiving portion 4 for disengaging from a driving portion 20 provided in a main assembly of apparatus, and such a portion of the cylindrical portion which supports the engaging projection and the releasing force receiving portion 4 is elastically deformable (in order to enhance or assist the elastic deformation, slits are formed at lateral sides of the region so as to extend to the free end of the cylindrical portion).
The engaging projection 3 is engaged with the driving portion 20 and functions to transmit the rotation force from the driving portion 20 to the toner bottle 1 through the engagement between the sealing member 2 and the driving portion 20.
In FIGS. 1 and 2, the main body 1A of the toner bottle is provided with the opening 1a at the one longitudinal end surface thereof, and a driving shaft 1b (portion to be engaged) is projected out of the opening 1a, the driving shaft 1b being integral with the main body 1A of the toner bottle and being provided in the opening 1a. The driving shaft 1b is disposed substantially coaxially with the opening 1a, and is slidably engaged with an engaging hole (not shown) formed in the sealing member 2.
The driving shaft 1b functions to transmit the rotational driving force from the main assembly of the apparatus to the main body 1A of the toner bottle through the sealing member 2, and the cross-sectional configuration of the driving shaft 1b is non-circular, for example, rectangular configuration, H shape, D shape or the like to transmit the rotational driving force. The driving shaft 1b is fixed on the main body 1A of the toner bottle by proper means.
The sealing member 2 has a sealing portion 2b for unsealably sealing the opening 1a of the toner bottle 1, and a coupling engagement portion 2c (cylindrical portion) in the form of a cylinder engageable with the driving portion 20 of the main assembly of the apparatus. An outer diameter of a large diameter portion of the sealing portion 2b is larger than the inner diameter of the opening 1a by a proper degree. The sealing portion 2b is press-fitted into the opening 1a, by which the opening 1a (toner supply opening) is sealed by the sealing member 2.
The coupling engagement portion 2c of the sealing member 2 has the engaging projection 3 for receiving the driving force from the main assembly of the apparatus, and slits 2e formed at lateral ends of the engaging projection 3. The engaging projection 3 is projected radially outwardly from the peripheral surface of the cylindrical portion of the coupling engagement portion 2c. The engaging projection 3 performs three different functions, namely, a coupling function for receiving the rotational driving force from the main assembly of apparatus, a transmitting function of transmitting the rotation to the toner bottle 1, and a locking function (retention function) for permitting relative sliding motion between the sealing member 2 and the main body 1A of the toner bottle 1 so as to automatically open and close the opening.
However, the conventional structures involve some problems. Among other things, first, because the coupling engagement portion 2c of the sealing member 2 is rather rigid, the impact of the driving force on the engaging projection 3 may not be easily absorbed by the coupling engagement portion 2c, which may lead to a speed wear and tear of the engaging projection 3 and other complications. Second, the rigidity of the coupling engagement portion 2c of the sealing member 2 may not facilitate a smooth engagement of the coupling engagement portion 2c of the sealing member 2 and a corresponding locking hole 20h formed in the driving portion 20 of the main assembly of apparatus, which also has an engaging rib 20a for rotating the toner bottle 1, and the engaging rib 20a abuts a drive receiving surface 3a to transmit the rotational driving force to the sealing member 2 after the engaging projection 3 is engaged with the locking hole 20h. 
Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.